KR20060131243A - Back light assembly and display apparatus having the same - Google Patents

Abstract

A backlight assembly and a display device having the same are provided to effectively diffuse a light, thereby improving the front visibility, by forming convex lens-shaped dot prism patterns on a light reflecting portion of a light guiding plate. A backlight assembly comprises a lamp(112) and a light guiding plate. The lamp is configured to emit a light. The light guiding plate includes a light entering portion(210), a light exiting portion(230) extended from one side of the light entering portion, and a light reflecting portion(220) facing the light exiting portion. The light reflecting portion of the light guiding plate has dot shaped prism patterns(240), wherein each of the prism patterns has at least one curved section.

Description

BACK LIGHT ASSEMBLY AND DISPLAY APPARATUS HAVING THE SAME}

1 is an exploded perspective view showing a backlight assembly according to the present invention.

FIG. 2 is a cross-sectional view illustrating a combined cross section of the backlight assembly illustrated in FIG. 1.

3 is a plan view illustrating a reflection part of the light guide plate illustrated in FIG. 1.

4 is a cross-sectional view taken along the line II ′ of FIG. 3.

FIG. 5 is a cross-sectional view illustrating another example of a prism pattern formed in the reflective part of the light guide plate illustrated in FIG. 1.

6 is a cross-sectional view illustrating still another example of a prism pattern formed in the reflecting portion of the light guide plate illustrated in FIG. 1.

FIG. 7 is a cross-sectional view illustrating still another example of a prism pattern formed in the reflecting portion of the light guide plate illustrated in FIG. 1.

8 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: backlight assembly 110: lamp unit

120: reflection sheet 200: light guide plate

210: incident part 220: reflecting part

230: exit portion 240: prism pattern

242: prism 300: display unit

310: liquid crystal display panel 320: driving circuit unit

The present invention relates to a backlight assembly and a display device having the same, and more particularly, to a backlight assembly and a display device having the same for improving visibility.

In general, the liquid crystal display (Liquid Crystal Display) is a flat panel display device that displays an image using a liquid crystal (Liquid Crystal), is thinner and lighter than other flat panel display devices, and has a low driving voltage and low power consumption It has advantages and is used extensively throughout the industry.

The liquid crystal display device includes a liquid crystal display panel including a thin film transistor (hereinafter, referred to as TFT) substrate, a color filter substrate facing the TFT substrate, and a liquid crystal layer interposed between the two substrates to change light transmittance. Liquid Crystal Display Panel). In addition, since the liquid crystal display device is a non-light emitting device that cannot emit light by itself, the liquid crystal display panel for displaying an image requires a backlight assembly for supplying light to the liquid crystal display panel.

The conventional backlight assembly includes a lamp for generating light and a light guide plate for guiding a path of light generated from a lamp disposed on a side of the lamp in a liquid crystal display panel direction. The light guide plate includes a dot pattern having a prism on a reflection surface opposite to the emission surface so that the light is emitted through one emission surface. In this case, the prism has a triangular cut surface. In addition, the surface of the prism is a smooth mirror surface.

In the dot pattern having the above-described shape, light is mirror reflected by the prism. Accordingly, the light is concentrated by the dot pattern, thereby increasing luminance, but there is a problem in that defects such as bright lines, white dots, and dark portions are generated. For this reason, there also exists a problem that front visibility falls.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a backlight assembly having a structure for improving visibility.

Another object of the present invention is to provide a display device having the backlight assembly.

The backlight assembly according to one aspect of the present invention described above includes a lamp and a light guide plate. The light guide plate has an incidence part to which light generated from a lamp is incident, an output part extending from one side of the incidence part, and a reflecting part in which a dot-shaped prism pattern is formed to face the exit part and has at least one curved surface in cross section. .

Here, the prism pattern includes a plurality of prisms in contact with each other, and the prisms have a convex lens shape in cross section.

According to an exemplary embodiment of the present invention, a display device includes a lamp for generating light, an incident part to which light generated from the lamp is incident, an exit part extending from one side of the incident part, and at least one curved surface facing the exit part. A backlight assembly including a light guide plate having a reflective part having a dot-shaped prism pattern, and a display panel configured to display an image using light supplied from the backlight assembly.

According to such a backlight assembly and a display device having the same, light may be diffused by forming a convex lens-shaped dot prism pattern on a reflecting portion of the light guide plate. Therefore, front visibility can be improved.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention.

1 is an exploded perspective view showing a backlight assembly according to the present invention, Figure 2 is a cross-sectional view showing a combined cross-section of the backlight assembly shown in FIG.

1 and 2, the backlight assembly 100 according to an embodiment of the present invention includes a lamp unit 110, a light guide plate 200, and a reflective sheet 120.

Here, the lamp unit 110 includes a lamp 112 and a lamp cover 114. The lamp unit 110 is disposed at both sides of the light guide plate 200 facing each other. Alternatively, the lamp unit 110 may be disposed only on one side of the light guide plate 200.

At least one lamp 112 is disposed in the lamp cover 114. The lamp 112 generates light in response to a power applied from an external inverter (not shown). As an example of the lamp 112, an elongated cylindrical cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp, CCFL). Alternatively, the lamp 112 may be formed of an external electrode fluorescent lamp (EEFL) in which electrodes are formed on outer surfaces of both ends.

The lamp cover 114 covers the three surfaces of the lamp 112 to protect the lamp 112. The lamp cover 114 is made of a material having a high reflectance or has a structure coated with a reflective material having a high reflectance on an inner surface thereof, and reflects light generated from the lamp 112 to the light guide plate 200 to improve light utilization efficiency. Let's do it.

The light guide plate 200 changes a traveling path of light incident from the lamp unit 110 and emits the light in a specific direction. The light guide plate 200 is made of a transparent material to transmit light. For example, the light guide plate 200 is made of polymethyl methacrylate (PMMA).

In addition, the light guide plate 200 extends from an incident part 210 to which light generated from the lamp 112 is incident, a reflecting part 220 extending from one side of the incident part 210, and the other side of the incident part 210. It includes a light emitting unit 230 facing the reflecting unit 220.

Prismatic patterns 240 having a dot shape are formed in the reflective part 220 of the light guide plate 200. Light incident to the inside of the light guide plate 200 through the incident part 210 of the light guide plate 200 is reflected and diffused by the prism patterns 240 to emit light 230 and the reflector (the light guide plate 200). It is emitted through 220).

The reflective sheet 120 is disposed on the reflective part 220 side of the light guide plate 200. The reflective sheet 120 reflects light leaking to the outside through the reflecting unit 220 of the light guide plate 200 and enters the light into the light guide plate 200 again. The reflective sheet 120 is made of a material having a high light reflectance. For example, the reflective sheet 120 is made of polyethylene terephthalate (PET) material, or polycarbonate (PC) material.

3 is a plan view illustrating a reflecting unit of the light guide plate illustrated in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line II ′ of FIG. 3.

3 and 4, prismatic patterns 240 having dot shapes are formed in the reflector 220 of the light guide plate 200. The prism patterns 240 have a circular shape in plan. In contrast, the prism patterns 240 may have a polygonal shape such as square or hexagon in plan.

 The prism patterns 240 protrude to a predetermined height from the surface of the reflector 220. In addition, the prism patterns 240 are formed of prisms 242 that are in contact with each other. The prisms 242 have a substantially convex lens shape in cross section perpendicular to the longitudinal direction.

As such, since the prisms 242 have a convex lens shape, the path of light L is greatly changed at the interface of the prisms 242, thereby spreading.

 That is, according to existing triangular prisms, the light collecting capability of the light L is improved to increase luminance, but the bright line generation and the front visibility are poor. However, according to the present embodiment, the convex lens-shaped prisms 242 are diffused in which the path of the light L is significantly changed as compared with the conventional one, and thus, the curved line defect does not occur and the front face is not generated. The visibility in is improved.

Although the prism 242 has a convex lens shape as an example, the upper end of the existing triangular prism, that is, the corner portion where two inclined surfaces meet may have a rounded shape. In this case, when the prisms 242 have a rounded shape, the front visibility is improved because the light is diffused in the rounded portion as compared with the conventional triangular shape.

FIG. 5 is a cross-sectional view illustrating another example of a prism pattern formed in the reflective part of the light guide plate illustrated in FIG. 1.

Referring to FIG. 5, in this embodiment, the prism patterns 250 are connected to each other and include prisms 252 having a substantially triangular cross section perpendicular to the longitudinal direction. The prisms 252 have irregular irregularities 254 formed on the surface by a corrosion treatment process.

As such, the light L is scattered at the interface of the prisms 252 by irregular irregularities 254 formed on the surfaces of the prisms 252, thereby improving front visibility as the light L is diffused.

6 is a cross-sectional view illustrating still another example of a prism pattern formed in the reflecting portion of the light guide plate illustrated in FIG. 1.

Referring to FIG. 6, in the present embodiment, the prism patterns 260 include prisms 262 that are connected to each other and have a substantially triangular cross section perpendicular to the longitudinal direction. The prism 262 includes diffusion beads 264 for scattering and diffusing the light L.

As such, the light L is scattered by the diffusion beads 264 inside the prism 262, and as a result, the light L is diffused, thereby improving the front visibility of the backlight assembly by the prism pattern 260.

FIG. 7 is a cross-sectional view illustrating still another example of a prism pattern formed in the reflecting portion of the light guide plate illustrated in FIG. 1.

Referring to FIG. 7, in this embodiment, the prism patterns 270 are connected to each other and include prisms 272 having a substantially triangular cross section perpendicular to the longitudinal direction. Scattering patterns 274 are formed on the surfaces of the prisms 272 to scatter and diffuse light L. Referring to FIG.

As such, the light L is scattered by the scattering pattern 274 formed on the surfaces of the prisms 272, thereby improving front visibility as the light L is diffused.

In the above example, the scattering pattern 274 is formed on the surfaces of the prisms 272, but a diffraction grating pattern may be formed on the surfaces of the prisms 272.

In addition, although only the case where the cross-section of the prisms shown in FIGS.

8 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 8, the liquid crystal display 500 according to the exemplary embodiment of the present invention includes a backlight assembly 100 and a display unit 600.

Here, the backlight assembly 100 is the same as the embodiment shown in Figures 1 to 4, the same number will be given and a detailed description thereof will be omitted.

The display unit 300 includes a liquid crystal display panel 310 for displaying an image using light supplied from the backlight assembly 100 and a driving circuit unit 320 for driving the liquid crystal display panel 310.

The liquid crystal display panel 310 is interposed between the first substrate 312, the second substrate 314 coupled to the first substrate 312, and between the first substrate 312 and the second substrate 314. It includes a liquid crystal layer (not shown).

The first substrate 312 is a substrate in which a thin film transistor (hereinafter, referred to as TFT), which is a switching element, is formed in a matrix form. For example, the first substrate 312 is made of glass. A data line and a gate line are respectively connected to the source terminal and the gate terminal of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal.

The second substrate 314 is a substrate in which RGB pixels for realizing color are formed in a thin film form. For example, the second substrate 314 is made of glass. The common electrode made of a transparent conductive material is formed on the second substrate 314.

In the liquid crystal display panel 310 having such a configuration, when power is applied to the gate terminal of the TFT and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. By such an electric field, the arrangement of liquid crystal molecules of the liquid crystal layer disposed between the first substrate 312 and the second substrate 314 is changed, and the transmittance of light supplied from the backlight assembly 100 is changed according to the arrangement change of the liquid crystal molecules. The image is changed to display an image of a desired gradation.

The driving circuit 320 includes a data printed circuit board 322 for supplying a data driving signal to the liquid crystal display panel 310, a gate printed circuit board 324 for supplying a gate driving signal to the liquid crystal display panel 310, and data. The data driving circuit film 326 connects the printed circuit board 322 to the liquid crystal display panel 310, and the gate drive circuit film 328 connects the gate printed circuit board 324 to the liquid crystal display panel 310. do. The data driving circuit film 326 and the gate driving circuit film 328 are made of, for example, a tape carrier package (TCP) or a chip on film (COF). Meanwhile, the gate printed circuit board 324 may be removed by forming separate signal wires on the liquid crystal display panel 310 and the gate driving circuit film 328.

According to such a backlight assembly and a liquid crystal display having the same, dot-shaped prism patterns having a cutting surface shape capable of diffusing light are formed in the reflecting portion of the light guide plate. The prism patterns have a cut surface in the shape of a convex lens.

Therefore, in the present invention, light is diffused by the prism patterns formed in the reflecting portion of the light guide plate.

Therefore, according to the present invention, since light is diffused by the prism patterns formed in the reflecting portion of the light guide plate, no bright line is generated and front visibility is improved.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (9)

A lamp for generating light; And And a light guide plate having an incident part to which light generated from the lamp is incident, an exit part extending from one side of the incident part, and a reflecting part having a dot-shaped prism pattern having at least one curved surface facing the exit part. Backlight assembly. The backlight assembly of claim 1, wherein the dot prism pattern includes a plurality of prisms in contact with each other, and the prisms have a convex lens shape in cross section. The backlight assembly of claim 1, wherein the dot prism pattern comprises a plurality of prisms that are connected to each other, and the prisms have a triangular shape with a rounded upper end. A lamp for generating light; And A light guide plate having an incident part to which light generated from the lamp is incident, an exit part extending from one side of the incident part, and a reflection part having a dot-shaped prism pattern having a predetermined pattern facing the exit part and scattering the light; Backlight assembly included. The method of claim 4, wherein The dot prism pattern includes a plurality of prisms connected to each other, the prisms have a triangular cross-section, The predetermined pattern is a backlight assembly, characterized in that the irregular pattern formed on the surface of the prism. The method of claim 4, wherein The dot prism pattern includes a plurality of prisms in contact with each other, And the predetermined pattern is diffusion beads formed in the prisms. The method of claim 4, wherein The dot prism pattern includes a plurality of prisms in contact with each other, The predetermined pattern is a backlight assembly, characterized in that the scattering pattern formed on the surface of the prism. A lamp for generating light, and A light guide plate having an incident part to which light generated from the lamp is incident, an exit part extending from one side of the incident part, and a reflecting part formed with a dot-shaped prism pattern facing the exit part and having at least one curved surface in cross section. A backlight assembly comprising a; And And a display panel configured to display an image by using light supplied from the backlight assembly. The method of claim 8, wherein the prism pattern comprises a plurality of prisms in contact with each other, And a predetermined pattern formed on a surface of the prisms to scatter the light.

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